Tips for Successful WLAN Site Planning

Craig J. Mathias is a principal with the wireless and mobile advisory firm Farpoint Group. A well-known technology analyst and consultant, he’s been active in the field for 20 years.

The history of wireless LANs has been punctuated by remarkable advances in reliability, security, throughput, manageability and price/performance. WLANs are appropriate solutions for sites/areas where wire can’t be installed or mobility is sought, as well as in cases where wireless is the less expensive alternative.

WLANs have become the new edge of the enterprise network, and upgrades are always on the horizon. Before rolling out or upgrading the network, heed these site planning tips to facilitate the process, minimize costs and maximize the utility of the resulting installation.

1. Understand objectives and user needs.

The first step is to understand what’s needed in each specific location, a task that is complicated by roaming users. A study of existing network traffic logs, user traffic types and an analysis of where users are likely to be when accessing the WLAN will help enormously. Be sure to provision enough capacity to serve the user base with bandwidth-hungry traffic such as video.

Don’t even think about older wireless technologies at this point — deploy the latest two- and three-stream 802.11n access points, Similarly, there’s no need to implement the upcoming 802.11ac products today, but keep an eye on wireless manufacturers’ future product roadmaps.

Factor in the reliability, availability and serviceability of the proposed deployment. A simple request for a proposal document makes a handy checklist to ensure all of an organization’s wireless needs are being considered.

2. Know the environment.

Perhaps surprisingly, the traditional site survey — one in which a qualified technician walks throughout the facility — isn’t always necessary, because most offices today have an open floor plan. Site surveys for radio frequency coverage are still recommended for relatively closed facilities, such as hospitals and industrial settings.

The traditional site survey optimizes for coverage rather than capacity. But sufficient coverage alone won’t make for happy or productive users, which is why the previous step can’t be overlooked.

A sweep with a spectrum analyzer to determine what systems are already operating in a given area can help pinpoint potential interference issues prior to rollout. Keep in mind, though, that contemporary WLAN management systems almost always do an excellent job of allocating radio channels and dealing with radio frequency-related challenges.

3. Install the WLAN.

Use the information gathered above to create the installation plan and decide where to place APs and wireless controllers. Most important, configure the system via the management console. Management functionality, the single most critical element in any systems purchase, can smooth operations and future scalability.

Unifying wired and wireless management deserves some attention. It’s no longer about thinking in terms of wired and wireless, but instead about viewing the LAN as an entity with two physical layers and everything in common above Layer 2.

Also, consider purchasing a few spare APs for rapid deployment should capacity issues arise — perhaps 10 percent of the total being deployed.

4. Test and verify functionality.

Now it’s time to power up. Installation tends to be a straightforward process, with the usual challenge being the logistical and mechanical considerations of running Ethernet cables to new APs. Some reconfiguration of Ethernet switches also may be required.

Double-check that the new WLAN performs as it should by running a few performance verification exercises. If the organization is upgrading, always apply a staged cutover to the new system.

5. Conduct ongoing monitoring.

Work on the WLAN is never really done. Regularly check to see how well users’ needs are being met, consider how operations might be refined and plan the next set of upgrades and additions.

The management console once again plays a major role here. Alerts and alarms indicating anomalous conditions are vital. Watching usage trends is the best way to smooth the next installation project — and there will be always be a next one.